法華玄論 1.73

1.73

復次欲說根本法輪，故說是經。根本法輪者，謂三世諸佛出世，為一大事因緣，即說一乘之道。但根緣未堪，故於一說三，即以一乘為本、三乘教為末。但大緣既熟，堪受一乘，今欲還說根本法輪，故說此經也。

Furthermore, wishing to preach the fundamental wheel of the Dharma, he preached this sūtra. As for the fundamental wheel of the Dharma: when the buddhas of the three times appear in the world for the sake of the one great causal condition, they preach the path of the one vehicle. However, because capacities and conditions were not yet capable, he preached three within the one, taking the one vehicle as the root and the teachings of the three vehicles as the branches. But when the great conditions had matured and beings were capable of receiving the one vehicle, wishing now to return to preaching the fundamental wheel of the Dharma, he preached this sūtra.